Magnetite (Fe3O4) thin films have been grown onto polycrystalline copper substrates via an electrochemical route. X-ray diffraction was employed to identify the crystal structure. Detailed surface morphological analysis was performed by atomic force microscopy and field-emission-gun scanning electron microscopy. Experimental results indicate the film surface is generally smooth, with a root-mean-square roughness of 12 nm over a 1 x 1 mu m field of view, although there exist small clusters due to anomalous growth. Additionally, annular dark-field scanning transmission electron microscopy reveals that film homogeneity is affected by the grain boundaries in the copper substrate. (C) 2007 The Electrochemical Society.